A Device for Sampling of Human Alveolar Breath for the Measurement of Expired Volatile Organic Compounds

Abstract

This report describes the development of a portable spirometer capable of collecting primarily alveolar breath into 1.8-L canisters for subsequent gas chromatographic/mass spectrometric (GC/MS) analysis. Based on CO₂ measurements, greater than 97% of the breath collected is alveolar in origin. Sample collection takes place in approximately two minutes. Clean air for inhalation is provided by two organic vapor respirator cartridges. Studies of the breakthrough volume of test compounds at both the 5- and 50-µg/m³ levels indicate that each cartridge filter can be used to sample over 300 L of air and that this volume is not altered by intermittent use and storage of the filter for up to five days. In experiments designed to mimic human breathing, recoveries of test compounds through the device at the 5-µg/m³ level ranged from 87 to 112%. Essentially no volatile organic compound (VOC) memory (i.e., adsorption carryover by the device) was measured at the 50-µg/m³ level. The data suggest that the device can be used successfully for organic compounds with volatilities greater than that of p-dichlorobenzene.